(1) Field of the Invention
The present invention relates to a binding apparatus for sealing a PVC (polyvinyl chloride) - or PE (polyethylene) -made bag containing cakes, bread or the like by twisting, at a portion near the opening or at the neck portion thereof, a ribbon-like plastic-made binding cord or tie having a core formed axially thereof, with a tag positioned under the tie on the bag near the neck thereof.
(2) Description of the Prior Art
It is well known to use a ribbon-like PVC-made tie having a wire provided axially therein, called "VINI-TIE (trade name)", which is to be twisted on a bag made of PE or the like and which contains cakes, bread or the like, at a portion near the open end or at the neck of the bag in order to seal the bag. Various apparatus of this type have been proposed as disclosed, for example, in the Mrs. Tange's U.S. Pat. No. 4,043,363 and Mr. Tsuda and Mrs. Tange's U.S. Pat. No. 4,087,951. The conventional binding cords or ties have axially provided therein a thin wire which makes the tie itself firm, easy to twist and also prevents the tie from returning to its initial state. The conventional binding apparatus capable of twisting the PVC-made tie is just a combination of a means of supplying a bag into place, means of delivering a tie into place on the bag and a means of twisting the tie around the bag. In this conventional apparatus, since the PVC-made tie has a wire provided therein so that both ends of the tie folded on a bag at the neck thereof is sufficiently firm, the tie can be twisted to a satisfactory extent by a means of catching the tie at the ends thereof, which may take the form of, for example, an S-shaped pawl.
Recently, however, the goods such as cakes, bread or the similar packed in a bag are checked to see if any metallic foreign matter exists therein during the goods inspection in the process of bagging or packaging of this kind. Namely, there is a problem that the wire in such PVC-made tie is detected as a foreign matter at the time of the inspection, so that the bag sealed with such tie is rejected. To avoid such inconvenience in the prior art, a plastic-made binding or tie having formed axially therein a plastic core instead of the wire has been developed for use in the field of packaging or bagging.
However, this plastic-made tie has a high resilience as compared with that of the ties having a fine wire axially provided therein, so that when it is used in the conventional binding apparatus, the binding pawl cannot catch the tie at the ends thereof, resulting in unsuccessful binding or in insufficient twisting of the tie which will slip off the bag neck.